Transmission of a common control in a beamforming system

ABSTRACT

Aspects of the present disclosure provide techniques for informing devices of the use of transmit and receive beams in a beamforming communication system. An exemplary method includes determining a plurality of beam directions for a device to use in different transmission time intervals (TTIs) of a TTI burst, and sending a directional transmission to the device indicating at least one of the beam directions.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application for patent claims priority to U.S. ProvisionalApplication No. 62/415,081, filed Oct. 31, 2016, which is assigned tothe assignee of the present application and hereby expresslyincorporated by reference herein in its entirety.

BACKGROUND Field of the Disclosure

Aspects of the present disclosure relate to wireless communications and,more particularly, to informing devices of the use of transmit andreceive beams in a beamforming communication system.

Description of Related Art

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includeLong Term Evolution (LTE) systems, code division multiple access (CDMA)systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems.

A wireless communication network may include a number of Node Bs thatcan support communication for a number of user equipments (UEs). A UEmay communicate with a Node B via the downlink and uplink. The downlink(or forward link) refers to the communication link from the Node B tothe UE, and the uplink (or reverse link) refers to the communicationlink from the UE to the Node B.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. An example of an emergingtelecommunication standard is new radio (NR, e.g., 5G radio access(RA)). NR is a set of enhancements to the LTE mobile standardpromulgated by Third Generation Partnership Project (3GPP). NR isdesigned to better support mobile broadband Internet access by improvingspectral efficiency, lowering costs, improving services, making use ofnew spectrum, and better integrate with other open standards using OFDMAwith a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL).In addition, NR supports beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation. However, as thedemand for mobile broadband access continues to increase, there exists aneed for further improvements in NR technology. Preferably, theseimprovements should be applicable to other multi-access technologies andthe telecommunication standards that employ these technologies.

SUMMARY

The systems, methods, and devices of the disclosure each have severalaspects, no single one of which is solely responsible for its desirableattributes. Without limiting the scope of this disclosure as expressedby the claims which follow, some features will now be discussed briefly.After considering this discussion, and particularly after reading thesection entitled “Detailed Description” one will understand how thefeatures of this disclosure provide advantages that include improvedcommunications between access points and stations in a wireless network.

Techniques for indicating beams to be used during a burst oftransmission time intervals (TTIs) in a wireless communications systemusing beamforming are described herein.

In an aspect, a method for wireless communication is provided. Themethod may be performed, for example, by an apparatus. The methodgenerally includes determining a plurality of beam directions for adevice to use in different transmission time intervals (TTIs) of a TTIburst, and sending a directional transmission to the device indicatingat least one of the beam directions.

In an aspect, a method for wireless communication is provided. Themethod may be performed, for example, by an apparatus. The methodgenerally includes determining a plurality of beam directions for adevice to use in different transmission time intervals (TTIs) of a TTIburst, determining, based at least on arrival of traffic for the device,whether to send the traffic to the device via a beam direction in theTTI burst, and sending a directional transmission to the deviceindicating at least one of the beam directions, if the determination wasto send the traffic to the device via the beam direction.

In an aspect, a method for wireless communication is provided. Themethod may be performed, for example, by an apparatus. The methodgenerally includes attempting to decode, in a control symbol, adirectional transmission, from a device, indicating at least one beamdirection for the apparatus to use in different transmission timeintervals (TTIs) of a TTI burst, and determining, if the directionaltransmission is decoded, not to monitor one or more TTIs of the TTIburst based on information in the directional transmission.

In an aspect, an apparatus for wireless communication is provided. Theapparatus generally includes a processing system configured to determinea plurality of beam directions for a device to use in differenttransmission time intervals (TTIs) of a TTI burst and to send adirectional transmission to the device indicating at least one of thebeam directions, and a memory coupled with the processing system.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe drawings set forth in detail certain illustrative features of theone or more aspects. These features are indicative, however, of but afew of the various ways in which the principles of various aspects maybe employed, and this description is intended to include all suchaspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above-recited features of the presentdisclosure can be understood in detail, a more particular description,briefly summarized above, may be had by reference to aspects, some ofwhich are illustrated in the appended drawings. It is to be noted,however, that the appended drawings illustrate only certain typicalaspects of this disclosure and are therefore not to be consideredlimiting of its scope, for the description may admit to other equallyeffective aspects.

FIG. 1 is a block diagram conceptually illustrating an exampletelecommunications system, according to aspects of the presentdisclosure.

FIG. 2 is a block diagram conceptually illustrating an example downlinkframe structure in a telecommunications system, according to aspects ofthe present disclosure.

FIG. 3 is a diagram illustrating an example uplink frame structure in atelecommunications system, according to aspects of the presentdisclosure.

FIG. 4 is a block diagram conceptually illustrating a design of anexample Node B and user equipment (UE), according to aspects of thepresent disclosure.

FIG. 5 is a diagram illustrating an example radio protocol architecturefor the user and control planes, according to aspects of the presentdisclosure.

FIG. 6 illustrates an example subframe resource element mapping,according to aspects of the present disclosure.

FIG. 7 illustrates an exemplary transmission timeline, according toaspects of the present disclosure.

FIG. 8 illustrates an example of a downlink-centric subframe, inaccordance with certain aspects of the present disclosure.

FIG. 9 illustrates an example of an uplink-centric subframe, inaccordance with certain aspects of the present disclosure.

FIG. 10 illustrates an exemplary transmission timeline, according toaspects of the present disclosure.

FIG. 11 illustrates an exemplary transmission timeline, according toaspects of the present disclosure.

FIG. 12 illustrates an exemplary transmission timeline, according toaspects of the present disclosure.

FIG. 13 illustrates an exemplary transmission timeline, according toaspects of the present disclosure.

FIG. 14 illustrates example operations that may be performed by anapparatus, according to aspects of the present disclosure.

FIG. 15 illustrates example operations that may be performed by anapparatus, according to aspects of the present disclosure.

FIG. 16 illustrates example operations that may be performed by anapparatus, according to aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure provide apparatus, methods, processingsystems, and computer readable mediums for indicating beams to be usedduring a burst of transmission time intervals (TTIs) in a wirelesscommunications system using beamforming.

Aspects of the present disclosure provide techniques for an apparatus tosignal indications of one or more beams that the apparatus may use fortransmitting or receiving communications from other devices during a TTIburst. For example, a BS may determine a set of beams that the BS willuse during a burst of subframes. The BS may transmit one or moreindications of the beams in control symbols of the burst. According toaspects of the present disclosure, one or more UEs may determine tomonitor for communications from the BS when the indication(s) indicate atransmit beam that is aimed at the UE and determine to transmit to theBS when the indication(s) indicate that the BS is using a receive beamaimed at the UE.

As described herein, a numerology of a wireless communications systemmay be based, at least in part, on a subcarrier or tone spacing, a shiftin frequency, and/or cyclic prefix (CP). Accordingly, a BS and UE in aheterogeneous numerology system may communicate using tones determinedbased on a numerology. Additionally or alternatively, the BS and UE maycommunicate using an RB defined using a numerology.

Various aspects of the disclosure are described more fully hereinafterwith reference to the accompanying drawings. This disclosure may,however, be embodied in many different forms and should not be construedas limited to any specific structure or function presented throughoutthis disclosure. Rather, these aspects are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art. Based on theteachings herein one skilled in the art should appreciate that the scopeof the disclosure is intended to cover any aspect of the disclosuredisclosed herein, whether implemented independently of or combined withany other aspect of the disclosure. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition toor other than the various aspects of the disclosure set forth herein. Itshould be understood that any aspect of the disclosure disclosed hereinmay be embodied by one or more elements of a claim.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any aspect described herein as “exemplary”is not necessarily to be construed as preferred or advantageous overother aspects.

Although particular aspects are described herein, many variations andpermutations of these aspects fall within the scope of the disclosure.Although some benefits and advantages of the preferred aspects arementioned, the scope of the disclosure is not intended to be limited toparticular benefits, uses, or objectives. Rather, aspects of thedisclosure are intended to be broadly applicable to different wirelesstechnologies, system configurations, networks, and transmissionprotocols, some of which are illustrated by way of example in thefigures and in the following description of the preferred aspects. Thedetailed description and drawings are merely illustrative of thedisclosure rather than limiting and the scope of the disclosure is beingdefined by the appended claims and equivalents thereof.

The techniques described herein may be used for various wirelesscommunication networks such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). NRis an emerging wireless communications technology under development inconjunction with the 5G Technology Forum (5GTF). 3GPP Long TermEvolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that useE-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described indocuments from an organization named “3rd Generation PartnershipProject” (3GPP). cdma2000 and UMB are described in documents from anorganization named “3rd Generation Partnership Project 2” (3GPP2). Thetechniques described herein may be used for the wireless networks andradio technologies mentioned above as well as other wireless networksand radio technologies.

For clarity, while aspects may be described herein using terminologycommonly associated with 3G and/or 4G wireless technologies, aspects ofthe present disclosure can be applied in other generation-basedcommunication systems, such as 5G and later, including NR technologies.

New radio (NR) may refer to radios configured to operate according to anew air interface (e.g., other than Orthogonal Frequency DivisionalMultiple Access (OFDMA)-based air interfaces) or fixed transport layer(e.g., other than Internet Protocol (IP)). NR may include Enhancedmobile broadband (eMBB) targeting wide bandwidth (e.g. 80 MHz beyond),millimeter wave (mmW) targeting high carrier frequency (e.g. 60 GHz),massive MTC (mMTC) targeting non-backward compatible MTC techniques, andmission critical targeting ultra reliable low latency communications(URLLC). For these general topics, different techniques are considered,such as coding, low-density parity check (LDPC), and polar. NR cell mayrefer to a cell operating according to the new air interface or fixedtransport layer. A NR Node B (e.g., 5G Node B) may correspond to one ormultiple transmission reception points (TRPs).

NR cells can be configured as access cell (ACells) or data only cells(DCells). For example, the RAN (e.g., a central unit or distributedunit) can configure the cells. DCells may be cells used for carrieraggregation or dual connectivity, but not used for initial access, cellselection/reselection, or handover. In some cases DCells may nottransmit synchronization signals—in some case cases DCells may transmitSS. TRPs may transmit downlink signals to UEs indicating the cell type.Based on the cell type indication, the UE may communicate with the TRP.For example, the UE may determine TRPs to consider for cell selection,access, handover, and/or measurement based on the indicated cell type.

In some cases, the UE can receive measurement configuration from theRAN. The measurement configuration information may indicate ACells orDCells for the UE to measure. The UE may monitor/detect measurementreference signals from the cells based on measurement configurationinformation. In some cases, the UE may blindly detect MRS. In some casesthe UE may detect MRS based on MRS-IDs indicated from the RAN. The UEmay report the measurement results.

Example Wireless Communications System

FIG. 1 illustrates an example wireless network 100 in which aspects ofthe present disclosure may be performed. For example, the wirelessnetwork may be a new radio (NR) or a 5G network.

According to aspects, the wireless network 100 may be a heterogeneousnumerology system, wherein UEs 120 within the network 100 may beasynchronous, have different intercarrier spacing, and/or have differentcyclic prefix lengths. According to aspects a BS, such as BS 110 a maysupport different services having different service requirements. Forexample, the BS 110 a may support subframe with different subcarrierspacing. The BS 110 a may communicate with UE 120 a using a firstsubcarrier spacing and may communicate with UE 120 b using a secondsubcarrier spacing. UEs 120 a, 120 b may be configured to operateaccording to one or more numerologies. In the manner a network maysupport subframes with different subcarrier spacings.

According to aspects, the subcarrier spacing associated with thedifferent service requirements may be scaled. As a non-limiting example,for illustrative purposes only, the subcarrier spacing may be 15 kHz, 30kHz, 60 kHz, 120 kHz, and so on (e.g., ×1, ×2, ×4, ×8, and so on . . .). According to another example, the subcarrier spacing may be 17.5 kHz,35 kHz, and so on (e.g., ×1, ×2, ×3, ×4, and so on). Aspects describedherein provide methods for tone allocation and resource block definitionfor heterogeneous numerology systems, which may be beneficial forscheduling devices and communicating with one or more devices inheterogeneous numerology systems.

As described herein, a numerology may be based, at least in part, on asubcarrier spacing and a shift in frequency. The BS 110 a and UE 120 amay communicate using tones determined using a numerology. Additionallyor alternatively, the BS 110 a and 120 a may communicate using an RBdefined using a numerology.

The BS 110 may be configured to perform the operations 1400, 1500, and1600, shown in FIGS. 14, 15, and 16. The UE 120 (e.g., UE 120 a) alsomay be configured to perform the operations 1400, 1500, and 1600, shownin FIGS. 14, 15, and 16. Furthermore, the BS 110 a and the UE 120 a maybe configured to perform other aspects described herein. The BS maycomprise and/or include a transmission reception point (TRP).

The system illustrated in FIG. 1 may be, for example, a long termevolution (LTE) network. The wireless network 100 may include a numberof Node Bs e.g., evolved Node Bs (eNodeBs or eNBs) or 5G Node Bs, 110and other network entities. A Node B may be a station that communicateswith the UEs and may also be referred to as a base station, an accesspoint, or a 5G Node B.

Each Node B 110 may provide communication coverage for a particulargeographic area. In 3GPP, the term “cell” can refer to a coverage areaof a Node B and/or a Node B subsystem serving this coverage area,depending on the context in which the term is used.

A Node B may provide communication coverage for a macro cell, a picocell, a femto cell, and/or other types of cell. A macro cell may cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscription. Apico cell may cover a relatively small geographic area and may allowunrestricted access by UEs with service subscription. A femto cell maycover a relatively small geographic area (e.g., a home) and may allowrestricted access by UEs having association with the femto cell (e.g.,UEs in a Closed Subscriber Group (CSG), UEs for users in the home,etc.). A Node B for a macro cell may be referred to as a macro Node B. ANode B for a pico cell may be referred to as a pico Node B. A Node B fora femto cell may be referred to as a femto Node B or a home Node B. Inthe example shown in FIG. 1, the Node Bs 110 a, 110 b and 110 c may bemacro Node Bs for the macro cells 102 a, 102 b and 102 c, respectively.The Node B 110 x may be a pico Node B for a pico cell 102 x. The Node Bs110 y and 110 z may be femto Node Bs for the femto cells 102 y and 102z, respectively. A Node B may support one or multiple (e.g., three)cells.

The wireless network 100 may also include relay stations. A relaystation is a station that receives a transmission of data and/or otherinformation from an upstream station (e.g., a Node B or a UE) and sendsa transmission of the data and/or other information to a downstreamstation (e.g., a UE or a Node B). A relay station may also be a UE thatrelays transmissions for other UEs. In the example shown in FIG. 1, arelay station 110 r may communicate with the Node B 110 a and a UE 120 rin order to facilitate communication between the Node B 110 a and the UE120 r. A relay station may also be referred to as a relay Node B, arelay, etc.

The wireless network 100 may be a heterogeneous network that includesNode Bs of different types, e.g., macro Node Bs, pico Node Bs, femtoNode Bs, relays, transmission reception points (TRPs), etc. Thesedifferent types of Node Bs may have different transmit power levels,different coverage areas, and different impact on interference in thewireless network 100. For example, macro Node Bs may have a hightransmit power level (e.g., 20 Watts) whereas pico Node Bs, femto NodeBs and relays may have a lower transmit power level (e.g., 1 Watt).

The wireless network 100 may support synchronous or asynchronousoperation. For synchronous operation, the Node Bs may have similar frametiming, and transmissions from different Node Bs may be approximatelyaligned in time. For asynchronous operation, the Node Bs may havedifferent frame timing, and transmissions from different Node Bs may notbe aligned in time. The techniques described herein may be used for bothsynchronous and asynchronous operation.

A network controller 130 may couple to a set of Node Bs and providecoordination and control for these Node Bs. The network controller 130may communicate with the Node Bs 110 via a backhaul. The Node Bs 110 mayalso communicate with one another, e.g., directly or indirectly viawireless or wireline backhaul.

The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughout thewireless network 100, and each UE may be stationary or mobile. A UE mayalso be referred to as a terminal, a mobile station, a subscriber unit,a station, etc. A UE may be a cellular phone, a personal digitalassistant (PDA), a wireless modem, a wireless communication device, ahandheld device, a laptop computer, a cordless phone, a wireless localloop (WLL) station, a tablet, a netbook, a smart book, etc. A UE may beable to communicate with macro Node Bs, pico Node Bs, femto Node Bs,relays, etc. In FIG. 1, a solid line with double arrows indicatesdesired transmissions between a UE and a serving Node B, which is a NodeB designated to serve the UE on the downlink and/or uplink. A dashedline with double arrows indicates interfering transmissions between a UEand a Node B.

LTE utilizes orthogonal frequency division multiplexing (OFDM) on thedownlink and single-carrier frequency division multiplexing (SC-FDM) onthe uplink. OFDM and SC-FDM partition the system bandwidth into multiple(K) orthogonal subcarriers, which are also commonly referred to astones, bins, etc. Each subcarrier may be modulated with data. Ingeneral, modulation symbols are sent in the frequency domain with OFDMand in the time domain with SC-FDM. The spacing between adjacentsubcarriers may be fixed, and the total number of subcarriers (K) may bedependent on the system bandwidth. For example, the spacing of thesubcarriers may be 15 kHz and the minimum resource allocation (called a‘resource block’) may be 12 subcarriers (or 180 kHz). Consequently, thenominal FFT size may be equal to 128, 256, 512, 1024 or 2048 for systembandwidth of 1.25, 2.5, 5, 10 or 20 megahertz (MHz), respectively. Thesystem bandwidth may also be partitioned into subbands. For example, asubband may cover 1.08 MHz (i.e., 6 resource blocks), and there may be1, 2, 4, 8 or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20MHz, respectively. New radio (NR) may use a different air interface,other than OFDM-based. NR networks may include entities such centralunits or distributed units.

While aspects of the examples described herein may be associated withLTE technologies, aspects of the present disclosure may be applicablewith other wireless communications systems, such as NR. NR may utilizeOFDM with a CP on the uplink and downlink and include support forhalf-duplex operation using TDD. A single component carrier bandwidth of100 MHZ may be supported. NR resource blocks may span 12 sub-carrierswith a sub-carrier bandwidth of 75 kHz over a 0.1 ms duration. Eachradio frame may consist of 50 subframes with a length of 10 ms.Consequently, each subframe may have a length of 0.2 ms. Each subframemay indicate a link direction (i.e., DL or UL) for data transmission andthe link direction for each subframe may be dynamically switched. Eachsubframe may include DL/UL data as well as DL/UL control data.Beamforming may be supported and beam direction may be dynamicallyconfigured. MIMO transmissions with precoding may also be supported.MIMO configurations in the DL may support up to 8 transmit antennas withmulti-layer DL transmissions up to 8 streams and up to 2 streams per UE.Multi-layer transmissions with up to 2 streams per UE may be supported.Aggregation of multiple cells may be supported with up to 8 servingcells. Alternatively, NR may support a different air interface, otherthan an OFDM-based. NR networks may include entities such central unitsor distributed units.

FIG. 2 shows a downlink (DL) frame structure used in a telecommunicationsystems (e.g., LTE). The transmission timeline for the downlink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 milliseconds (ms)) and may bepartitioned into 10 sub-frames with indices of 0 through 9. Eachsub-frame may include two slots. Each radio frame may thus include 20slots with indices of 0 through 19. Each slot may include L symbolperiods, e.g., 7 symbol periods for a normal cyclic prefix (as shown inFIG. 2) or 6 symbol periods for an extended cyclic prefix. The 2L symbolperiods in each sub-frame may be assigned indices of 0 through 2L−1. Theavailable time frequency resources may be partitioned into resourceblocks. Each resource block may cover N subcarriers (e.g., 12subcarriers) in one slot.

In LTE, a Node B may send a primary synchronization signal (PSS) and asecondary synchronization signal (SSS) for each cell in the Node B. Theprimary and secondary synchronization signals may be sent in symbolperiods 6 and 5, respectively, in each of sub-frames 0 and 5 of eachradio frame with the normal cyclic prefix, as shown in FIG. 2. Thesynchronization signals may be used by UEs for cell detection andacquisition. The Node B may send a Physical Broadcast Channel (PBCH) insymbol periods 0 to 3 in slot 1 of sub-frame 0. The PBCH may carrycertain system information.

The Node B may send a Physical Control Format Indicator Channel (PCFICH)in only a portion of the first symbol period of each sub-frame, althoughdepicted in the entire first symbol period in FIG. 2. The PCFICH mayconvey the number of symbol periods (M) used for control channels, whereM may be equal to 1, 2 or 3 and may change from sub-frame to sub-frame.M may also be equal to 4 for a small system bandwidth, e.g., with lessthan 10 resource blocks. In the example shown in FIG. 2, M=3. The Node Bmay send a Physical HARQ Indicator Channel (PHICH) and a PhysicalDownlink Control Channel (PDCCH) in the first M symbol periods of eachsub-frame (M=3 in FIG. 2). The PHICH may carry information to supporthybrid automatic retransmission (HARQ). The PDCCH may carry informationon uplink and downlink resource allocation for UEs and power controlinformation for uplink channels. Although not shown in the first symbolperiod in FIG. 2, it is understood that the PDCCH and PHICH are alsoincluded in the first symbol period. Similarly, the PHICH and PDCCH arealso both in the second and third symbol periods, although not shownthat way in FIG. 2. The Node B may send a Physical Downlink SharedChannel (PDSCH) in the remaining symbol periods of each sub-frame. ThePDSCH may carry data for UEs scheduled for data transmission on thedownlink. The various signals and channels in LTE are described in 3GPPTS 36.211, entitled “Evolved Universal Terrestrial Radio Access(E-UTRA); Physical Channels and Modulation,” which is publiclyavailable.

The Node B may send the PSS, SSS and PBCH in the center 1.08 MHz of thesystem bandwidth used by the Node B. The Node B may send the PCFICH andPHICH across the entire system bandwidth in each symbol period in whichthese channels are sent. The Node B may send the PDCCH to groups of UEsin certain portions of the system bandwidth. The Node B may send thePDSCH to specific UEs in specific portions of the system bandwidth. TheNode B may send the PSS, SSS, PBCH, PCFICH and PHICH in a broadcastmanner to all UEs, may send the PDCCH in a unicast manner to specificUEs, and may also send the PDSCH in a unicast manner to specific UEs.

A number of resource elements may be available in each symbol period.Each resource element may cover one subcarrier in one symbol period andmay be used to send one modulation symbol, which may be a real orcomplex value. Resource elements not used for a reference signal in eachsymbol period may be arranged into resource element groups (REGs). EachREG may include four resource elements in one symbol period. The PCFICHmay occupy four REGs, which may be spaced approximately equally acrossfrequency, in symbol period 0. The PHICH may occupy three REGs, whichmay be spread across frequency, in one or more configurable symbolperiods. For example, the three REGs for the PHICH may all belong insymbol period 0 or may be spread in symbol periods 0, 1 and 2. The PDCCHmay occupy 9, 18, 36 or 72 REGs, which may be selected from theavailable REGs, in the first M symbol periods. Only certain combinationsof REGs may be allowed for the PDCCH.

A UE may know the specific REGs used for the PHICH and the PCFICH. TheUE may search different combinations of REGs for the PDCCH. The numberof combinations to search is typically less than the number of allowedcombinations for the PDCCH. A Node B may send the PDCCH to the UE in anyof the combinations that the UE will search.

A UE may be within the coverage of multiple Node Bs. One of these NodeBs may be selected to serve the UE. The serving Node B may be selectedbased on various criteria such as received power, path loss,signal-to-noise ratio (SNR), etc.

FIG. 3 is a diagram 300 illustrating an example of an uplink (UL) framestructure in a telecommunications system (e.g., LTE). The availableresource blocks for the UL may be partitioned into a data section and acontrol section. The control section may be formed at the two edges ofthe system bandwidth and may have a configurable size. The resourceblocks in the control section may be assigned to UEs for transmission ofcontrol information. The data section may include all resource blocksnot included in the control section. The UL frame structure results inthe data section including contiguous subcarriers, which may allow asingle UE to be assigned all of the contiguous subcarriers in the datasection.

A UE may be assigned resource blocks 310 a, 310 b in the control sectionto transmit control information to a Node B. The UE may also be assignedresource blocks 320 a, 320 b in the data section to transmit data to theNode B. The UE may transmit control information in a physical UL controlchannel (PUCCH) on the assigned resource blocks in the control section.The UE may transmit only data or both data and control information in aphysical UL shared channel (PUSCH) on the assigned resource blocks inthe data section. A UL transmission may span both slots of a subframeand may hop across frequency.

A set of resource blocks may be used to perform initial system accessand achieve UL synchronization in a physical random access channel(PRACH) 330. The PRACH 330 carries a random sequence and cannot carryany UL data/signaling. Each random access preamble occupies a bandwidthcorresponding to six consecutive resource blocks. The starting frequencyis specified by the network. That is, the transmission of the randomaccess preamble is restricted to certain time and frequency resources.There is no frequency hopping for the PRACH. The PRACH attempt iscarried in a single subframe (1 ms) or in a sequence of few contiguoussubframes and a UE can make only a single PRACH attempt per frame (10ms).

FIG. 4 illustrates example components of the base station 110 and UE 120illustrated in FIG. 1, which may be used to implement aspects of thepresent disclosure. One or more components of the BS 110 and UE 120 maybe used to practice aspects of the present disclosure. For example,antennas 452, Tx/Rx 222, processors 466, 458, 464, and/orcontroller/processor 480 of the UE 120 and/or antennas 434, processors460, 420, 438, and/or controller/processor 440 of the BS 110 may be usedto perform the operations described herein and illustrated withreference to FIGS. 14-16. The BS 110 may comprise a TRP. As illustrated,the BS/TRP 110 and UE 120 may communicate using tone alignment and/or RBdefinition in a heterogeneous numerology system.

FIG. 4 shows a block diagram of a design of a base station/Node B/TRP110 and a UE 120, which may be one of the base stations/Node Bs/TRPs andone of the UEs in FIG. 1. For a restricted association scenario, thebase station 110 may be the macro Node B 110 c in FIG. 1, and the UE 120may be the UE 120 y. The base station 110 may also be a base station ofsome other type. The base station 110 may be equipped with antennas 434a through 434 t, and the UE 120 may be equipped with antennas 452 athrough 452 r.

At the base station 110, a transmit processor 420 may receive data froma data source 412 and control information from a controller/processor440. The control information may be for the PBCH, PCFICH, PHICH, PDCCH,etc. The data may be for the PDSCH, etc. The transmit processor 420 mayprocess (e.g., encode and symbol map) the data and control informationto obtain data symbols and control symbols, respectively. The transmitprocessor 420 may also generate reference symbols, e.g., for the PSS,SSS, and cell-specific reference signal. A transmit (TX) multiple-inputmultiple-output (MIMO) processor 430 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, and/or thereference symbols, if applicable, and may provide output symbol streamsto the modulators (MODs) 432 a through 432 t. Each modulator 432 mayprocess a respective output symbol stream (e.g., for OFDM, etc.) toobtain an output sample stream. Each modulator 432 may further process(e.g., convert to analog, amplify, filter, and upconvert) the outputsample stream to obtain a downlink signal. Downlink signals frommodulators 432 a through 432 t may be transmitted via the antennas 434 athrough 434 t, respectively. The transmit processor 420, TX MIMOprocessor 430, modulators 432 a-432 t, and antennas 434 a-434 t may becollectively referred to as a transmit chain of the base station.

At the UE 120, the antennas 452 a through 452 r may receive the downlinksignals from the base station 110 and may provide received signals tothe demodulators (DEMODs) 454 a through 454 r, respectively. Eachdemodulator 454 may condition (e.g., filter, amplify, downconvert, anddigitize) a respective received signal to obtain input samples. Eachdemodulator 454 may further process the input samples (e.g., for OFDM,etc.) to obtain received symbols. A MIMO detector 456 may obtainreceived symbols from all the demodulators 454 a through 454 r, performMIMO detection on the received symbols if applicable, and providedetected symbols. A receive processor 458 may process (e.g., demodulate,deinterleave, and decode) the detected symbols, provide decoded data forthe UE 120 to a data sink 460, and provide decoded control informationto a controller/processor 480. The receive processor 458, MIMO detector456, demodulators 454 a-454 r, and antennas 452 a-452 t may becollectively referred to as a receive chain of the UE.

On the uplink, at the UE 120, a transmit processor 464 may receive andprocess data (e.g., for the PUSCH) from a data source 462 and controlinformation (e.g., for the PUCCH) from the controller/processor 480. Thetransmit processor 464 may also generate reference symbols for areference signal. The symbols from the transmit processor 464 may beprecoded by a TX MIMO processor 466 if applicable, further processed bythe demodulators 454 a through 454 r (e.g., for SC-FDM, etc.), andtransmitted to the base station 110. The transmit processor 464, TX MIMOprocessor 466, modulators 454 a-454 r, and antennas 452 a-452 r may becollectively referred to as a transmit chain of the UE. At the basestation 110, the uplink signals from the UE 120 may be received by theantennas 434, processed by the modulators 432, detected by a MIMOdetector 436 if applicable, and further processed by a receive processor438 to obtain decoded data and control information sent by the UE 120.The receive processor 438 may provide the decoded data to a data sink439 and the decoded control information to the controller/processor 440.The receive processor 438, MIMO detector 436, demodulators 432 a-432 t,and antennas 434 a-434 t may be collectively referred to as a receivechain of the base station.

The controllers/processors 440 and 480 may direct the operation at thebase station 110 and the UE 120, respectively. The processor 440 and/orother processors and modules at the base station 110 may perform ordirect, e.g., the execution of various processes for the techniquesdescribed herein. The processor 480 and/or other processors and modulesat the UE 120 may also perform or direct, e.g., the execution of thefunctional blocks illustrated in FIGS. 18-21, and/or other processes forthe techniques described herein. The memories 442 and 482 may store dataand program codes for the base station 110 and the UE 120, respectively.A scheduler 444 may schedule UEs for data transmission on the downlinkand/or uplink.

FIG. 5 is a diagram 500 illustrating an example of a radio protocolarchitecture for the user and control planes in LTE. The radio protocolarchitecture for the UE and the Node B is shown with three layers: Layer1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer andimplements various physical layer signal processing functions. The L1layer will be referred to herein as the physical layer 506. Layer 2 (L2layer) 508 is above the physical layer 506 and is responsible for thelink between the UE and Node B over the physical layer 506.

In the user plane, the L2 layer 508 includes a media access control(MAC) sublayer 510, a radio link control (RLC) sublayer 512, and apacket data convergence protocol (PDCP) 514 sublayer, which areterminated at the Node B on the network side. Although not shown, the UEmay have several upper layers above the L2 layer 508 including a networklayer (e.g., IP layer) that is terminated at the PDN gateway 118 on thenetwork side, and an application layer that is terminated at the otherend of the connection (e.g., far end UE, server, etc.).

The PDCP sublayer 514 provides multiplexing between different radiobearers and logical channels. The PDCP sublayer 514 also provides headercompression for upper layer data packets to reduce radio transmissionoverhead, security by ciphering the data packets, and handover supportfor UEs between Node Bs. The RLC sublayer 512 provides segmentation andreassembly of upper layer data packets, retransmission of lost datapackets, and reordering of data packets to compensate for out-of-orderreception due to hybrid automatic repeat request (HARQ). The MACsublayer 510 provides multiplexing between logical and transportchannels. The MAC sublayer 510 is also responsible for allocating thevarious radio resources (e.g., resource blocks) in one cell among theUEs. The MAC sublayer 510 is also responsible for HARQ operations.

In the control plane, the radio protocol architecture for the UE andNode B is substantially the same for the physical layer 506 and the L2layer 508 with the exception that there is no header compressionfunction for the control plane. The control plane also includes a radioresource control (RRC) sublayer 516 in Layer 3 (L3 layer). The RRCsublayer 516 is responsible for obtaining radio resources (i.e., radiobearers) and for configuring the lower layers using RRC signalingbetween the Node B and the UE.

FIG. 6 shows two exemplary subframe formats 610 and 620 for the downlinkwith the normal cyclic prefix. The available time frequency resourcesfor the downlink may be partitioned into resource blocks. Each resourceblock may cover 12 subcarriers in one slot and may include a number ofresource elements. Each resource element may cover one subcarrier in onesymbol period and may be used to send one modulation symbol, which maybe a real or complex value.

Subframe format 610 may be used for a Node B equipped with two antennas.A CRS may be transmitted from antennas 0 and 1 in symbol periods 0, 4, 7and 11. A reference signal is a signal that is known a priori by atransmitter and a receiver and may also be referred to as a pilot. A CRSis a reference signal that is specific for a cell, e.g., generated basedon a cell identity (ID). In FIG. 6, for a given resource element withlabel R_(a), a modulation symbol may be transmitted on that resourceelement from antenna a, and no modulation symbols may be transmitted onthat resource element from other antennas. Subframe format 620 may beused for a Node B equipped with four antennas. A CRS may be transmittedfrom antennas 0 and 1 in symbol periods 0, 4, 7 and 11 and from antennas2 and 3 in symbol periods 1 and 8. For both subframe formats 610 and620, a CRS may be transmitted on evenly spaced subcarriers, which may bedetermined based on cell ID. Different Node Bs may transmit their CRSson the same or different subcarriers, depending on their cell IDs. Forboth subframe formats 610 and 620, resource elements not used for theCRS may be used to transmit data (e.g., traffic data, control data,and/or other data).

The PSS, SSS, CRS and PBCH in LTE are described in 3GPP TS 36.211,entitled “Evolved Universal Terrestrial Radio Access (E-UTRA); PhysicalChannels and Modulation,” which is publicly available.

An interlace structure may be used for each of the downlink and uplinkfor FDD in LTE. For example, Q interlaces with indices of 0 through Q−1may be defined, where Q may be equal to 4, 6, 8, 10, or some othervalue. Each interlace may include subframes that are spaced apart by Qframes. In particular, interlace q may include subframes q, q+Q, q+2Q,etc., where q∈{0, . . . , Q−1}.

The wireless network may support hybrid automatic retransmission (HARQ)for data transmission on the downlink and uplink. For HARQ, atransmitter (e.g., a Node B) may send one or more transmissions of apacket until the packet is decoded correctly by a receiver (e.g., a UE)or some other termination condition is encountered. For synchronousHARQ, all transmissions of the packet may be sent in subframes of asingle interlace. For asynchronous HARQ, each transmission of the packetmay be sent in any subframe.

A UE may be located within the coverage area of multiple Node Bs. One ofthese Node Bs may be selected to serve the UE. The serving Node B may beselected based on various criteria such as received signal strength,received signal quality, pathloss, etc. Received signal quality may bequantified by a signal-to-noise-and-interference ratio (SINR), or areference signal received quality (RSRQ), or some other metric. The UEmay operate in a dominant interference scenario in which the UE mayobserve high interference from one or more interfering Node Bs.

New radio (NR) may refer to radios configured to operate according awireless standard, such as 5G (e.g. wireless network 100). NR mayinclude Enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g.80 MHz beyond), millimeter wave (mmW) targeting high carrier frequency(e.g. 60 GHz), massive MTC (mMTC) targeting non-backward compatible MTCtechniques, and mission critical targeting ultra reliable low latencycommunications (URLLC).

NR cell may refer to a cell operating according in the NR network. A NRNode B (e.g., Node B 110) may correspond to one or multiple transmissionreception points (TRPs). As used herein, a cell may refer to acombination of downlink (and potentially also uplink) resources. Thelinking between the carrier frequency of the downlink resources and thecarrier frequency of the uplink resources is indicated in the systeminformation (SI) transmitted on the downlink resources. For example,system information can be transmitted in a physical broadcast channel(PBCH) carrying a master information block (MIB).

NR RAN architecture may include a central unit (CU) (e.g., networkcontroller 130). The CU may be an Access node controller (ANC). The CUterminates backhaul interface to RAN-CN, terminates backhaul interfaceto neighbor RAN node. The RAN may include a Distributed unit that may beone or more TRPs that may be connected to one or more ANCs (not shown).TRPs may advertise System Information (e.g., Global TRP ID), may includePDCP/RLC/MAC functions, may comprise one or more antenna ports, may beconfigured to individually (dynamic selection) or jointly (jointtransmission), and may serve traffic to the UE.

Heterogeneous numerology wireless communication systems may refer tosystems in which UEs may be asynchronous, have different intercarrierspacing and/or have different cyclic prefix lengths. According toaspects of the present disclosure, tones for different numerologies maybe aligned. A numerology may be based on a subcarrier spacing and a toneshift. As described herein, regardless of the numerology, the tones fromthe heterogeneous numerology wireless systems may be frequency-aligned.

Example Transmission of a Common Control in a Beamforming System

According to aspects of the present disclosure, in a beamforming system,a broadcast signal transmitted in a particular direction (e.g., from aBS) may only reach a subset of UEs or other devices. For dynamic TDDoperation, a transmitter may transmit a slot or frame format indicatorto indicate a slot or frame structure for the next N slots or subframes.However, multiple users (e.g., UEs, BSs) may be scheduled in the N slotsor subframes, and the users may share the transmission resources (e.g.,the available frequencies for the N slots or subframes) in either a timedivision multiplexing (TDM) manner, a frequency division multiplexing(FDM) manner, or a spatial multiplexing manner, like multi-usermultiple-input multiple-output (MU-MIMO). Those users may have differentbeamforming or beam pairing association(s) with a transmitter, such asan eNB or a next generation Node B (gNB). The transmitter (e.g., a BS,an eNB, a gNB) may transmit the slot or frame format indicator in one ora few OFDM symbols at the beginning of the N slots or subframes or in anadditional transmission during those N slots/subframes. Fornon-beamforming systems, transmitting one such indicator (e.g.,broadcast to all devices in range) may be sufficient to indicate a slotor frame structure, for the next N slots or subframes, to all devices inrange.

FIG. 7 illustrates an exemplary transmission timeline 700, according toaspects of the present disclosure. An exemplary control region 702includes three control symbols that are transmitted by an apparatus(e.g., by BS 110 a in FIG. 1) to indicate beams used in fivetransmission time intervals (TTIs) (e.g., slots, sub-slots, orsubframes) in a data region 704. The data region may contain additionalcontrol information. Each of the control symbols indicates beams used bythe apparatus for one or multiple TTIs for one direction. For example,BS 110 a transmits the control symbol 710 to transmit control for onedirection, and the control symbol indicates a beam used for transmissionby the BS in TTIs 722 and 724 in the exemplary timeline. In theexemplary timeline, the control symbols at 702 can be part of the firstTTI (e.g., TTI 722 in the exemplary timeline).

According to aspects of the present disclosure, each TTI (e.g., TTIs722, 724, 730, 732, 740, shown in FIG. 7) may have a different downlinkto uplink configuration. For example, TTI 730 can be an uplink-centric(UL-centric) subframe while TTIs 722, 732, 724, and 740 are downlink ordownlink-centric (DL-centric) subframes. Downlink-centric subframes mayinclude an uplink portion, while uplink-centric subframes may include adownlink portion.

FIG. 8 is a diagram 800 showing an example of a DL-centric subframe,which may be used to communicate in the wireless network 100. TheDL-centric subframe may include a control portion 802. The controlportion 802 may exist in the initial or beginning portion of theDL-centric subframe. The control portion 802 may include variousscheduling information and/or control information corresponding tovarious portions of the DL-centric subframe. In some configurations, thecontrol portion 802 may be a physical downlink control channel (PDCCH),as indicated in FIG. 8. The DL-centric subframe may also include a DLdata portion 804. The DL data portion 804 may sometimes be referred toas the payload of the DL-centric subframe. The DL data portion 804 mayinclude the communication resources utilized to communicate DL data fromthe scheduling entity (e.g., UE or BS) to the subordinate entity (e.g.,UE). In some configurations, the DL data portion 804 may be a physicalDL shared channel (PDSCH).

The DL-centric subframe may also include a common UL portion 806. Thecommon UL portion 806 may sometimes be referred to as an UL burst, acommon UL burst, and/or various other suitable terms. The common ULportion 806 may include feedback information corresponding to variousother portions of the DL-centric subframe. For example, the common ULportion 806 may include feedback information corresponding to thecontrol portion 802. Non-limiting examples of feedback information mayinclude an ACK signal, a NACK signal, a HARQ indicator, and/or variousother suitable types of information. The common UL portion 806 mayinclude additional or alternative information, such as informationpertaining to random access channel (RACH) procedures, schedulingrequests (SRs), and various other suitable types of information. Asillustrated in FIG. 8, the end of the DL data portion 804 may beseparated in time from the beginning of the common UL portion 806. Thistime separation may sometimes be referred to as a gap, a guard period, aguard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g., receptionoperation by the subordinate entity (e.g., UE)) to UL communication(e.g., transmission by the subordinate entity (e.g., UE)). One ofordinary skill in the art will understand that the foregoing is merelyone example of a DL-centric subframe and alternative structures havingsimilar features may exist without necessarily deviating from theaspects described herein.

FIG. 9 is a diagram 900 showing an example of an UL-centric subframe,which may be used to communicate in the wireless network 100. TheUL-centric subframe may include a control portion 902. The controlportion 902 may exist in the initial or beginning portion of theUL-centric subframe. The control portion 902 in FIG. 9 may be similar tothe control portion described above with reference to FIG. 8. TheUL-centric subframe may also include an UL data portion 904. The UL dataportion 904 may sometimes be referred to as the payload of theUL-centric subframe. The UL portion may refer to the communicationresources utilized to communicate UL data from a subordinate entity(e.g., UE) to a scheduling entity (e.g., UE or BS). In someconfigurations, the control portion 902 may be a physical DL controlchannel (PDCCH).

As illustrated in FIG. 9, the end of the control portion 902 may beseparated in time from the beginning of the UL data portion 904. Thistime separation may sometimes be referred to as a gap, guard period,guard interval, and/or various other suitable terms. This separationprovides time for the switch-over from DL communication (e.g.,transmission operation by the scheduling entity) to UL communication(e.g., reception by the scheduling entity). The UL-centric subframe mayalso include a common UL portion 906. The common UL portion 906 in FIG.9 may be similar to the common UL portion 806 described above withreference to FIG. 8. The common UL portion 806 may additionally oralternatively include information pertaining to a channel qualityindicator (CQI), sounding reference signals (SRSs), and various othersuitable types of information. One of ordinary skill in the art willunderstand that while foregoing is merely one example of an UL-centricsubframe and alternative structures having similar features may existwithout necessarily deviating from the aspects described herein.

FIG. 10 illustrates an exemplary transmission timeline 1000, accordingto aspects of the present disclosure. In the exemplary timeline, anindicator is transmitted by an apparatus (e.g., by BS 110 a in FIG. 1),in each control symbol 1010, 1012, 1014 in a control region 1002, andused to indicate beams used by the apparatus in five transmission timeintervals (TTIs) (e.g., slots, sub-slots, or subframes) 1020, 1022,1030, 1032, 1040 in a data region 1004. The data region may containadditional control information. The control region and TTIs maycollectively be referred to as a TTI burst or a burst.

According to aspects of the present disclosure, an indicator such asthose transmitted in the control symbols 1010, 1012, and 1014 mayinclude one or a combination of pieces of information. One piece ofinformation the indicator may include is a beam direction indicator,where, for N TTIs (e.g., slots or subframes), the apparatus may have acapability to indicate M directions, where M<=N (e.g., a beam directionindicator may be capable of indicating one of three directions, and a BSmay use the beam direction indicator for a period of five TTIs). Anotherpiece of information the indicator may include is downlink and/or uplinksplit information for one or more of the TTIs. Yet another piece ofinformation the indicator may include is a duration of the burst (e.g.,a number of slots or a number of subframes). Other pieces of informationthe indicator may include are numerology parameters (e.g., tone spacingand/or CP duration) used by the apparatus in the burst, where multiplenumerologies may be used in the burst. Still other information that theindicator may include is an indication that one or more uplink controlregions (considering the control region 1002 as a downlink controlregion) are scheduled in one or more of the TTIs (e.g., slots orsubframes) in the burst.

FIG. 11 illustrates an exemplary transmission timeline 1100, accordingto aspects of the present disclosure. In the exemplary timeline, anindicator is transmitted by an apparatus (e.g., by BS 110 a in FIG. 1),in each control symbol 1110, 1112, and 1114 in a control region 1102,and used to indicate beams used by the apparatus in five transmissiontime intervals (TTIs) (e.g., slots or subframes) 1120, 1122, 1130, 1132,and 1140 in a data region 1104. The data region may contain additionalcontrol information. The control region and TTIs may collectively bereferred to as a TTI burst or a burst.

According to aspects of the present disclosure, the indicator mayindicate one or a combination of pieces of information. A first piece ofinformation the indicator may include is receive beam information forthe transmitting apparatus for an uplink portion (consideringtransmissions by the transmitting device to be downlink) in the burst. Aspecific beam index may be signaled such that a receiving device knowsthat the transmitting apparatus will prepare a receive beam (of thetransmitting apparatus) in a specific direction at a specific time inthe burst. This may enable a device receiving the indicator to transmitto the apparatus transmitting the indicator using a beam matching theindicated receive beam at the indicated time. For example, an eNB (e.g.,eNB 110 a in FIG. 1) transmits an indicator of three directions 1, 2,and 3 in a downlink transmission. In the example, the eNB prepares areceive beam for the eNB to receive in direction 2 at the end of TTI(e.g., slot or subframe) 4. In the example, the eNB preparing andindicating the receive beam may enable a UE (e.g., UE 120 a in FIG. 1),which is located in a direction from the eNB that corresponds to thereceive beam, to autonomously (e.g., without being scheduled by the eNB)transmit to the eNB in another (e.g., higher) frequency, because the UEknows from the indicator that the eNB is ready to receive in a directioncorresponding to the UE. In aspects of the present disclosure, a UE maytransmit a beam recovery signal using the advertised information, wherebeam recovery means the UE may have lost an existing active beam pair toa serving gNB, and the UE is trying to signal to the gNB that a new beamdirection has been identified and that the new beam direction matcheswith the advertised receive beam direction.

FIG. 12 illustrates an exemplary transmission timeline 1200, accordingto aspects of the present disclosure. In the exemplary timeline, anindicator is transmitted by an apparatus (e.g., by BS 110 a in FIG. 1),in a first control symbol 1210 of a control region 1202 including twoother control symbols 1212, 1214, and used to indicate beams used by theapparatus in five transmission time intervals (TTIs) (e.g., slots orsubframes) 1220, 1222, 1230, 1232, 1240 in a data region 1204. The dataregion may contain additional control information. The control regionand TTIs may collectively be referred to as a TTI burst or a burst.According to aspects of the present disclosure, the indicator may betransmitted in a broadcast manner, such that any device within range ofthe apparatus can receive it and determine beams to be used by thetransmitting apparatus.

FIG. 13 illustrates an exemplary transmission timeline 1300, accordingto aspects of the present disclosure. In the exemplary timeline, anindicator is transmitted by an apparatus (e.g., by BS 110 a in FIG. 1),in a directional manner (e.g., via a beam) in each control symbol 1310,1312, 1314 of a control region 1302 and used to indicate beams used bythe apparatus in five transmission time intervals (TTIs) (e.g., slots orsubframes) 1320, 1322, 1330, 1332, 1340 in a data region 1304. The dataregion may contain additional control information. The control regionand TTIs may collectively be referred to as a TTI burst or a burst.

According to aspects of the present disclosure, the indicator may betransmitted in each beam direction by being repeated in each controlsymbol 1310, 1312, 1314, and each control symbol may be transmittedusing the corresponding beam direction.

According to aspects of the present disclosure, the indicator may bescrambled, with the scrambling based on a control symbol index of thecontrol symbol in which the indicator is transmitted.

According to aspects of the present disclosure, each indicator may betransmitted on frequency resources selected based on a control symbolindex of the control symbol in which the indicator is transmitted.

According to aspects of the present disclosure, an indicator may bedirection specific, with the indicator indicating only a beam or beamsthat are used when transmitting the indicator.

According to aspects of the present disclosure, the indicator may be UEspecific, with the indicator indicating only a beam corresponding to(e.g., receivable by) a UE or other device in one direction from theapparatus.

According to aspects of the present disclosure, the indicator may begroup specific, with the indicator indicating only a beam correspondingto (e.g., receivable by) a group of UEs or other devices in onedirection from the apparatus.

According to aspects of the present disclosure, the indicator describedin FIG. 13 may be transmitted in each symbol of the control region bybeing jointly encoded over the symbols in the control region. Specificresources (e.g. frequency resources) may be reserved in all or a subsetof a control region, and after encoding, the indicator may be mapped tothose resources. From a symbol index of a control symbol, a receivingdevice (e.g., a UE) can derive the coded bits, and thus, using one or asubset of symbols, the receiving device can decode the indicator.

According to aspects of the present disclosure, the indicators describedabove with reference to FIGS. 7 and 10-13 may be transmitted via a layer1 (e.g. PHY) signal.

According to aspects of the present disclosure, the indicators describedabove with reference to FIGS. 7 and 10-13 may be transmitted via acontrol channel (e.g., a PDCCH).

According to aspects of the present disclosure, the indicators describedabove with reference to FIGS. 7 and 10-13 may be transmitted by anapparatus (e.g., eNB 110 a shown in FIG. 1) and activated and/ordeactivated by the apparatus. That is, an apparatus may send anindicator that a beam will be used in a TTI and later send a signal(e.g., a control channel) indicating that the beam will not actually beused during part or all of that TTI. A device (e.g., UE 120 a shown inFIG. 1) receiving such an indicator and signal may determine that thebeam is not intended for the device and not monitor a TTI or portion ofthe TTI if the apparatus signals that the indicator is activated. If theapparatus signals that the indicator is deactivated, then the device maymonitor the corresponding TTI or portion of the TTI, because theapparatus may transmit a signal that the device can receive.

According to aspects of the present disclosure, an apparatus (e.g., eNB110 a shown in FIG. 1) may send an indicator and then determine not touse the indicated beams and also determine not to transmit a signalindicating the indicator is deactivated. For example, the apparatus maydetermine to schedule only non-beamformed transmissions intended fordevices that monitor regardless of what the indicator indicates duringthe burst, and the apparatus may then transmit broadcast transmissionsduring the burst.

According to aspects of the present disclosure, an apparatus (e.g., eNB110 a shown in FIG. 1) may signal to one or more other devices (e.g., UE120 a shown in FIG. 1) that the apparatus may use such an indicator, asdescribed above. The other devices may determine to monitor for theindicator and, upon receiving an indicator, the other device maydetermine when to monitor for beamformed transmissions from theapparatus.

According to aspects of the present disclosure, an apparatus (e.g., eNB110 a shown in FIG. 1) may determine not to transmit an indicator asdescribed above.

As previously mentioned an indicator can be transmitted via a layer 1signal or via a control channel. According to aspects of the presentdisclosure, a receiving device (e.g., UE 120 a shown in FIG. 1) mayattempt to decode such an indicator in each potential control symbol.Once decoded, a receiving device may determine not to monitor some ofthe TTIs (e.g., slots or subframes) based on the decoded informationcarried in the indicator. For example, a device receiving thetransmissions shown in transmission timeline 1300 in FIG. 13 maydetermine that the device cannot receive any beam indicated in TTI 1340and, based on that determination, determine not to monitor fortransmissions from an apparatus during TTI 1340.

According to aspects of the present disclosure, a receiving device(e.g., UE 120 a shown in FIG. 1) may, if the device is unable to decodeany indicator, determine to monitor each TTI (e.g., slot or subframe)for a control channel that may schedule transmissions for the receivingdevice.

FIG. 14 illustrates example operations 1400 that may be performed by anapparatus, according to aspects of the present disclosure. The apparatusmay be BS 110 a or UE 120 a in FIG. 1, which may include one or morecomponents illustrated in FIG. 4.

Operations 1400 begin at 1402 with the apparatus determining a pluralityof beam directions for a device to use in different transmission timeintervals (TTIs) of a TTI burst. For example, BS 110 a may determine aset of three beam directions for UE 120 a to use in five TTIs of a TTIburst, such as the TTI 1000 burst shown in FIG. 10. In the example, thebeam of TTIs 1 and 4 may point in the direction of UE 120 a.

At 1404, the apparatus sends a directional transmission to the deviceindicating at least one of the beam directions. The directionaltransmission may comprise, for example, one or more of the indicatorsdescribed above with reference to FIGS. 7 and 10-13. Continuing theexample from above, BS 110 a may send a directional transmission to UE120 a (e.g., using the beams to be used during TTIs 1 and 4) indicatingthat the BS will use a beam with a direction matching the direction toUE 120 a during TTIs 1 and 4 of the TTI burst.

FIG. 15 illustrates example operations 1500 that may be performed by anapparatus, according to aspects of the present disclosure. The apparatusmay be BS 110 a or UE 120 a in FIG. 1, which may include one or morecomponents illustrated in FIG. 4.

Operations 1500 begin at 1502 with the apparatus determining a pluralityof beam directions for a device to use in different transmission timeintervals (TTIs) of a TTI burst. For example, BS 110 a may determine aset of three beam directions for UE 120 a to use in five TTIs of a TTIburst, such as the TTI 1000 burst shown in FIG. 10. In the example, thebeam of TTIs 1 and 4 may point in the direction of UE 120 a.

At 1504, the apparatus determines, based at least on arrival of trafficfor the device, whether to send the traffic to the device via a beamdirection in the TTI burst. Continuing the example from above, BS 110 amay receive traffic for UE 120 a and determine to send the traffic to UE120 a using the beams the BS determined to use in TTIs 1 and 4, becausethe BS is aware that those beams are in a direction matching thedirection to UE 120 a.

At 1506, the apparatus sends a directional transmission to the deviceindicating at least one of the beam directions, if the determination wasto send the traffic to the device via the beam direction. Thedirectional transmission may comprise, for example, one or more of theindicators described above with reference to FIGS. 7 and 10-13.Continuing the example from above, BS 110 a may send a directionaltransmission to UE 120 a (e.g., using the beams to be used during TTIs 1and 4) indicating that the BS will use a beam with a direction matchingthe direction to UE 120 a during TTIs 1 and 4 of the TTI burst.

FIG. 16 illustrates example operations 1600 that may be performed by anapparatus, according to aspects of the present disclosure. The apparatusmay be BS 110 a or UE 120 a in FIG. 1, which may include one or morecomponents illustrated in FIG. 4.

Operations 1600 begin at 1602 with the apparatus attempting to decode,in a control symbol, a directional transmission, from a device,indicating at least one beam direction for the apparatus to use indifferent transmission time intervals (TTIs) of a TTI burst. Forexample, UE 120 a may attempt to decode a directional transmission fromBS 110 a, in a control symbol (e.g., control symbol 1010 shown in FIG.10), wherein the directional transmission indicates that the BS will usea beam with a direction not matching the direction to the UE in TTIs 1and 4 of a TTI burst, such as TTI burst 1000 shown in FIG. 10.

At 1604, the apparatus determines, if the directional transmission isdecoded, not to monitor one or more TTIs of the TTI burst based oninformation in the directional transmission. The directionaltransmission may comprise, for example, one or more of the indicatorsdescribed above with reference to FIGS. 7 and 10-13. Continuing theexample from above, the UE may determine not to monitor TTIs 1 and 4 ofthe TTI burst 1000, because the UE successfully decoding the controlsymbol 1010 and determined that transmissions in TTIs 1 and 4 will be onbeams that do not match the direction from the BS to the UE.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isspecified, the order and/or use of specific steps and/or actions may bemodified without departing from the scope of the claims.

As used herein, a phrase referring to “at least one of” a list of itemsrefers to any combination of those items, including single members. Asan example, “at least one of: a, b, or c” is intended to cover a, b, c,a-b, a-c, b-c, and a-b-c, as well as any combination with multiples ofthe same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b,b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c).

As used herein, the term “determining” encompasses a wide variety ofactions. For example, “determining” may include calculating, computing,processing, deriving, investigating, looking up (e.g., looking up in atable, a database or another data structure), ascertaining and the like.Also, “determining” may include receiving (e.g., receiving information),accessing (e.g., accessing data in a memory) and the like. Also,“determining” may include resolving, selecting, choosing, establishingand the like.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but is to be accorded the full scope consistentwith the language claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. All structural andfunctional equivalents to the elements of the various aspects describedthroughout this disclosure that are known or later come to be known tothose of ordinary skill in the art are expressly incorporated herein byreference and are intended to be encompassed by the claims. Moreover,nothing disclosed herein is intended to be dedicated to the publicregardless of whether such disclosure is explicitly recited in theclaims. No claim element is to be construed under the provisions of 35U.S.C. § 112, sixth paragraph, unless the element is expressly recitedusing the phrase “means for” or, in the case of a method claim, theelement is recited using the phrase “step for.”

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components withsimilar numbering.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a userterminal 120 (see FIG. 1), a user interface (e.g., keypad, display,mouse, joystick, etc.) may also be connected to the bus. The bus mayalso link various other circuits such as timing sources, peripherals,voltage regulators, power management circuits, and the like, which arewell known in the art, and therefore, will not be described any further.The processor may be implemented with one or more general-purpose and/orspecial-purpose processors. Examples include microprocessors,microcontrollers, DSP processors, and other circuitry that can executesoftware. Those skilled in the art will recognize how best to implementthe described functionality for the processing system depending on theparticular application and the overall design constraints imposed on theoverall system.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer-readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product/computerreadable medium for performing the operations presented herein. Forexample, such a computer program product may comprise acomputer-readable medium having instructions stored (and/or encoded)thereon, the instructions being executable by one or more processors toperform the operations described herein.

Further, it should be appreciated that modules and/or other appropriatemeans for performing the methods and techniques described herein can bedownloaded and/or otherwise obtained by a user terminal and/or basestation as applicable. For example, such a device can be coupled to aserver to facilitate the transfer of means for performing the methodsdescribed herein. Alternatively, various methods described herein can beprovided via storage means (e.g., RAM, ROM, a physical storage mediumsuch as a compact disc (CD) or floppy disk, etc.), such that a userterminal and/or base station can obtain the various methods uponcoupling or providing the storage means to the device. Moreover, anyother suitable technique for providing the methods and techniquesdescribed herein to a device can be utilized.

It is to be understood that the claims are not limited to the preciseconfiguration and components illustrated above. Various modifications,changes and variations may be made in the arrangement, operation anddetails of the methods and apparatus described above without departingfrom the scope of the claims.

What is claimed is:
 1. A method for wireless communications by anapparatus, comprising: determining a plurality of beam directions for adevice to use in different transmission time intervals (TTIs) of a TTIburst; sending to the device a directional transmission comprisingpieces of information, in one or more control symbols, indicating atleast one of the beam directions; sending, in each of the beamdirections, the directional transmission or another directionaltransmission indicating the beam directions, wherein sending thedirectional transmission and the other directional transmissioncomprises sending the directional transmission and the other directionaltransmission via corresponding control symbols and correspondingfrequencies, each control symbol having a different index; andscrambling each directional transmission based on the index of thecorresponding control symbol.
 2. The method of claim 1, wherein thedirectional transmission further indicates at least one of a downlink touplink split of the TTI burst, a duration of the TTI burst, and anuplink control region of at least one TTI of the TTI burst.
 3. Themethod of claim 1, wherein the directional transmission indicates atleast one numerology parameter used in the TTI burst.
 4. The method ofclaim 3, wherein the at least one numerology parameter comprises atleast one of tone spacing or cyclic prefix (CP) length.
 5. The method ofclaim 1, wherein a TTI comprises a plurality of subframes.
 6. The methodof claim 1, wherein a TTI comprises a plurality of slots or sub-slots.7. The method of claim 1, wherein the directional transmission furtherindicates the apparatus will receive on the at least one of the beamdirections during a TTI, or a slot or sub-slot of the TTI burst.
 8. Themethod of claim 7, further comprising: receiving a signal from thedevice or another device via one of the indicated at least one of thebeam directions.
 9. The method of claim 7, further comprising:configuring a receive chain of the apparatus to receive via one of theindicated at least one of the beam directions.
 10. The method of claim1, wherein the directional transmission or the other directionaltransmission indicates a beam direction of the corresponding directionaltransmission.
 11. The method of claim 10, wherein: sending thedirectional transmission and the other directional transmissioncomprises sending the directional transmission and the other directionaltransmission via corresponding control symbols and correspondingfrequencies, each control symbol having a different index; and themethod further comprises selecting the corresponding frequency for eachdirectional transmission based on the index of the corresponding controlsymbol.
 12. The method of claim 1, further comprising: sending, to eachof a plurality of devices, the directional transmission or anotherdirectional transmission indicating at least a beam directioncorresponding to the device.
 13. The method of claim 12, wherein:sending the directional transmission and the other directionaltransmissions comprises sending the directional transmission and theother directional transmissions via corresponding control symbols andcorresponding frequencies, each control symbol having a different index;and the method further comprises selecting the corresponding frequencyfor each directional transmission based on the index of thecorresponding control symbol.
 14. The method of claim 1, furthercomprising: sending, to each group of devices of a plurality of groupsof devices, the directional transmission or the other directionaltransmission indicating at least a beam direction corresponding to thegroup of devices.
 15. The method of claim 1, further comprising:communicating with the device via an active transmit and receive beampair prior to sending the directional transmission; and obtaining anindication that the apparatus has lost the existing transmit and receivebeam pair, wherein sending the directional transmission comprisessending a beam recovery signal in response to obtaining the indication.16. The method of claim 1, wherein the directional transmission or theother directional transmission indicate the beam directions and whereinsending the directional transmission and the other directionaltransmissions comprises: jointly encoding each directional transmissionfor transmission over a set of control symbols, each control symbolhaving a different index; mapping the jointly encoded directionaltransmissions to frequency resources; and transmitting each directionaltransmission via the set of control symbols on the frequency resources.17. The method of claim 1, wherein sending the directional transmissioncomprises: sending the directional transmission via a layer 1 signal.18. The method of claim 1, wherein sending the directional transmissioncomprises: sending the directional transmission via a control channel.19. The method of claim 1, further comprising: receiving anotherdirectional transmission from the device on one of the beam directions.20. The method of claim 1, further comprising: determining, based atleast on arrival of traffic for the device, to send the traffic to thedevice via a beam direction in the TTI burst, wherein the sending to thedevice the directional transmission is in response to determining tosend the traffic to the device via the beam direction and thedirectional transmission comprises the traffic.
 21. The method of claim20, further comprising: signaling to the device that the apparatus iscapable of sending the directional transmission.
 22. An apparatus forwireless communications, comprising: a processing system configured to:determine a plurality of beam directions for a device to use indifferent transmission time intervals (TTIs) of a TTI burst; send to thedevice a directional transmission comprising pieces of information, inone or more control symbols, indicating at least one of the beamdirections; send, in each of the beam directions, the directionaltransmission or another directional transmission indicating the beamdirections, wherein sending the directional transmission and the otherdirectional transmission comprises sending the directional transmissionand the other directional transmission via corresponding control symbolsand corresponding frequencies, each control symbol having a differentindex; and scramble each directional transmission based on the index ofthe corresponding control symbol; and a memory coupled with theprocessing system.
 23. A method for wireless communications by anapparatus, comprising: determining a plurality of beam directions for adevice to use in different transmission time intervals (TTIs) of a TTIburst; sending to the device a directional transmission comprisingpieces of information, in one or more control symbols, indicating atleast one of the beam directions; sending, in each of the beamdirections, the directional transmission or another directionaltransmission indicating the beam directions, wherein sending thedirectional transmission and the other directional transmissionscomprises sending the directional transmission and the other directionaltransmissions via corresponding control symbols and correspondingfrequencies, each control symbol having a different index; and selectingthe corresponding frequency for each directional transmission based onthe index of the corresponding control symbol.
 24. An apparatus forwireless communications, comprising: a processing system configured to:determine a plurality of beam directions for a device to use indifferent transmission time intervals (TTIs) of a TTI burst; send to thedevice a directional transmission comprising pieces of information, inone or more control symbols, indicating at least one of the beamdirections; send, in each of the beam directions, the directionaltransmission or another directional transmission indicating the beamdirections, wherein sending the directional transmission and the otherdirectional transmission comprises sending the directional transmissionand the other directional transmission via corresponding control symbolsand corresponding frequencies, each control symbol having a differentindex; and select the corresponding frequency for each directionaltransmission based on the index of the corresponding control symbol; anda memory coupled with the processing system.
 25. A method for wirelesscommunications by an apparatus, comprising: attempting to decode, in acontrol symbol, a directional transmission, from a device, indicating atleast one beam direction for different transmission time intervals(TTIs) of a TTI burst; determining, when the directional transmission isdecoded, not to monitor one or more TTIs of the TTI burst based oninformation in the directional transmission; and determining to monitorall TTIs of the TTI burst, when the directional transmission is notdecoded.
 26. The method of claim 25, further comprising: determining totransmit a transmission to the device, when the directional transmissionis decoded and when the directional transmission indicates the devicewill receive on a beam corresponding to the apparatus.